Wayne Daily, age 10, of St. Catharines, Ont,, for his question!
Which is the oldest mountain range?
Mountains live to be very, very old. But they do not live forever. The world's youngest mountains are the coastal ranges of California. This baby is but a million years old and may be still growing. The Alps and the Himalayas are in the prime of life. They are about 50 million years old and we know that Mt. Everest in the Himalayas is still adding to his tremendous height; The Apennines, the Pyrenees and the Caucasus are in his same age group.
The stately Rockies and the Andes are older mountains. They did their growing between 60 and 130 million years ago. Though they have finished growing they are still in the prime of life and will be for several million years. However, the wind and weather have started to attach their tall peaks, wearing away the jagged edges and. weakening some of the rocks.
The Sierra Nevada was born about 150 million years ago. They are high, though not so high as the Rockies, and their growth ended long ago. For several million years the weather has been busy wearing down their tall peaks. Frost and heat have cracked. open their high boulders. Gushing rains have gouged deep gorges in their sides.
The southern Appalachians are oven older. They were born about 200 million years ago. These mountains wore once much higher than they are now. The wind and the weather have rounded the crests and made rich soil on the slopes where forests now grow. The northern Appalachians are older and more worn by about 100 million years.
About 300 million years ago volcanos raged in Maine and New Brunswick. Mountains were growing in Greenland, Scandinavia and Great Britain. These ancient ranges are so worn that only their roots remain. Older still are the Killarney mountains of Canada, Wisconsin and. Minnesota. Now no more than gentle hills, those mountains were in the prime of life about 500 million years ago.
But the oldest mountains we know of can look upon the Killarneys, the Sierra Nevada, the Rockies and all the other ranges on earth as more children. These most ancient of ancients arc the Laurentians of eastern Canada. This region of the earth began to rise somewhere between 1,000 million anal 2,000 million years ago. We cannot guess what these, earth's first mountains, were li'ke or how tall they were. The wind and weather have long since worn away their once proud crowns.
Much later this range and surrounding regions were lifted up in a great tableland covering two million square miles ‑ the Laurentian Plateau. This plateau was dry land when the unborn Rockies and Appalachians were under the sea.